1. Field of the Invention
The invention relates to a measuring device for contactless capture or determination of an angle of rotation or of a linear motion.
2. Prior Art
From French Patent Disclosure FR 90 15 223, a measuring device is known in which a stator and a rotor are moved relative to one another. Between the stator and the rotor, each of which comprises magnetically conductive material, there is a small air gap. In the rotor, a first annular permanent magnet which is radially polarized is disposed over a length of 180.degree.. In the remaining region of the stator, also encompassing 180.degree., there is a second annular permanent magnet with opposite polarization. The stator also has two diametrically opposed air gaps. In at least one of these air gaps, there is a Hall sensor. In the rotary motion of the rotor relative to the stator, the intensity of the magnetic field passing through the Hall sensor varies. The linear measurement range of the measurement signal thus generated is limited, however, to a magnitude of approximately.+-.75.degree.. Moreover, this linear measurement range has a change of sign. It is possible to correct this in a complicated and expensive way in an ensuing electrical circuit.
It is also known, for measuring linear motions, to displace permanent magnets relative to a magnet-field-sensitive element. In this respect it is also known to carry the flux of the permanent magnet with the aid of magnetically conductive parts.